摘要:
A process for preparing ketones by so-called “crossed aldol condensation” of a ketone with an aldehyde in the presence of a catalyst system consisting of approximately equimolar amounts of a secondary amine and of a carboxylic acid containing at least 2 C atoms, to form an &agr;,&bgr;-unsaturated ketone, and, where appropriate, subsequent catalytic hydrogenation. The process is used in particular for preparing 6-methyl-3-hepten-2-one by reacting acetone with isovaleraldehyde, and for preparing its hydrogenation product, 6-methylheptan-2-one, which is an important precursor for numerous active substances, in particular for preparing lipid-soluble vitamins such as vitamin E.
摘要:
Cyclic urea derivatives of the formula I ##STR1## in which X, X', Y, Y' and Z can have various meanings, are prepared by a) reacting a urea derivative of the formula II ##STR2## with a diketone of the formula III ##STR3## and b) hydrogenating the product from step a) in the presence of a metal-containing catalyst.
摘要:
The present invention relates to a process for preparing trioxime derivatives of the formula I in which the substituents R1 and R2 are identical or different and each is cyano, alkyl, haloalkyl or cycloalkyl, and R3 and R4 are identical or different and each is alkyl, haloalkyl, cycloalkyl, alkylcarbonyl or arylalkyl, by the following reaction steps in water without isolation of the intermediates: A) nitrosation of 1,3-diketones of the formula II to give monooximes of the formula III, B) oximation of III with hydroxylamine derivatives of the formula IV H2N—OR3′ IV in which R3′ is hydrogen or a group R3 to give bisoximes of the formula V, C) alkylation of V with alkylating agents or acylation of V with acylating agents to give compounds of the formula VI and D) subsequent oximation of VI with hydroxylamine to give compounds of the formula I.
摘要:
Amines are prepared by reacting aldehydes or ketones at elevated temperature under elevated pressure with nitrogen compounds selected from the group of ammonia, primary and secondary amines, and with hydrogen in the presence of a catalyst containing copper, wherein the catalytically active mass of the catalyst contains, before the reduction with hydrogen, 20 to 85% by weight of oxygen-containing compounds of zirconium, calculated as ZrO2, 1 to 30% by weight of oxygen-containing compounds of copper, calculated as CuO, 14 to 70% by weight of oxygen-containing compounds of nickel, calculated as NiO, 0 to 5% by weight of oxygen-containing compounds of molybdenum, calculated as MoO3, and 0 to 10% by weight of oxygen-containing compounds of aluminum, calculated as Al2O3.
摘要翻译:胺在升高的温度下在升高的温度下与选自氨,伯胺和仲胺的氮化合物和氢气在含催化剂的聚合物的存在下反应制备,其中催化剂活性物质含有, 在用氢还原之前,以ZrO 2计为20〜85重量%的含氧化合物,以30重量%计,氧化铝为14〜70重量%,氧化铝为100重量% 以NiO表示的镍化合物,以MoO 3计为0〜5重量%的含氧化合物的钼和0〜10重量%的按Al 2 O 3计算的含氧化合物的铝。
摘要:
Optically active amines are racemized by reaction of the optically active amine in the gas phase at elevated temperature in the presence of hydrogen and a hydrogenation or dehydrogenation catalyst.
摘要:
In a process for racemizing optically active amines by reacting the optically active amine in the presence of hydrogen and a hydrogenation or dehydrogenation catalyst at elevated temperature, the reaction is carried out in liquid phase and the catalyst comprises the catalytically active constituents copper, silver, iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium and/or platinum and a support material selected from the group consisting of aluminum oxide, zirconium dioxide, titanium dioxide, carbon and/or oxygen compounds of silicon.
摘要:
Process for the preparation of anthraquinones of the general formula I ##STR1## in which R.sup.1, R.sup.2, R.sup.3 and R.sup.4, which can be identical or different, are hydrogen, a C.sub.1 -C.sub.8 -alkyl or C.sub.2 -C.sub.8 -alkenyl radical, in which 1,4-naphthoquinone is reacted with a 1,3-diene of the general formula II ##STR2## in a cycloaddition step to give the corresponding tetrahydroanthraquinone and the tetrahydroanthraquinone is oxidized with oxygen in the presence of a basic catalyst to give the anthraquinone, in which both the cycloaddition step and the oxidation step are carried out in the presence of an aqueous diluent.Preferably, the cycloaddition step and oxidation step are carried out at a reaction temperature between 90 and 110.degree. C. and at atmospheric pressure.
摘要:
A process for the preparation of racemic amines of the formula I ##STR1## where R.sup.1 and R.sup.2 are different and R.sup.1, R.sup.2, R.sup.3 are alkyl, cycloalkyl, arylalkyl, aryl, heteroaryl and heterocyclic radicals and R.sup.3 can also be hydrogen, where the radicals can bear substituents selected from the group consisting of alkyl, cycloalkyl, alkoxy, aryloxy, amino, alkylamino and dialkylamino, which comprises simultaneously reacting in situ the corresponding optically active amine I and the secondary alcohol of the formula II and/or the unsymmetrical ketone of the formula III ##STR2## and the amine of the formula R.sup.3 NH.sub.2 in the presence of hydrogen and a hydrogenation catalyst or dehydrogenation catalyst at elevated temperature.
摘要:
A process for preparing unsaturated nitriles of the formula I ##STR1## where R, R.sup.1 and R.sup.2 are each independently of one another alkyl or alkenyl each having 1-20 carbon atoms or cycloalkyl or cycloalkenyl each having 3-12 carbon atoms and any two of the radicals R, R.sup.1 and R.sup.2 may be part of a saturated or unsaturated ring and R.sup.1 and R.sup.2 may also be hydrogen and n is 0 or 1-20, by dehydration of oximes of the formula II ##STR2## where R, R.sup.1, R.sup.2 and n are as defined above, comprises dehydrating in the gas or liquid phase at from 150.degree. to 300.degree. C. over a heterogeneous catalyst consisting of an oxidic, carbidic or nitridic support doped with basic oxides and/or hydroxides or compounds which are converted into said oxides or hydroxides under the reaction conditions, or of said basic oxides.
摘要:
The invention relates to a process for preparing essentially formic acid-free N-alkyl-N′-methylalkyleneureas of the formula with R1=H or CH3, R2=CnH2n+1 with n=1-4 and x=0 or 1, from the corresponding alkyleneureas by reaction with monomeric or polymerized formaldehyde in the presence of formic acid. This entails feeding the mixture, obtained in the reaction, of N-alkyl-N′-methylalkyleneurea and formic acid to the upper region of a distillation column, distilling without further additions and removing essentially formic acid-free N-alkyl-N′-methylalkyleneurea in the lower region of the column. The process parameters are set so that the pressure in the upper region of the column is at a higher level than in the lower region of the column, and the difference in pressure between the upper and lower regions of the column is from 10 to 100 mbar, and the temperature in the lower region of the column is higher than in the upper region of the column, with the difference in temperature between the upper and lower regions of the column being from 40° C. to 210° C.